Complex karyotype in a low grade phyllodes tumor of the breast

Cytogenetic analysis of a phyllodes tumor of low grade malignancy disclosed the karyotype 52∼55,XX, −1,+5,+7,+9,+10,+11,-15,+18,−19,+20,der(21)t(1;21)(p13;q22),+mar1×2∼4,+mar2[cp18]/46,XX[2]. This study shows that a complex chromosome karyotype can be found in low-grade phyllodes tumors and is not necessarily a sign of extreme malignancy of these neoplasms.